An 87th minute equaliser from Carlos Tevez gave Manchester United a 1-1 draw at Olympique Lyon while Barcelona beat Celtic 3-2 away in the Champions League last 16 first-leg matches on Wednesday.
Holders AC Milan survived an onslaught by Arsenal to earn a 0-0 draw at the Emirates stadium and Turkish champions Fenerbahce edged Spanish rivals Sevilla 3-2 in Istanbul to set up an intriguing return leg in a fortnight.
United's transfer target Karim Benzema gave French champions and league leaders Lyon a deserved 54th minute lead with a fine shot on the turn before second half substitute Tevez levelled from close range.
Lyon dominated the opening half as Alex Ferguson's defensive 4-5-1 formation looked out of sorts and the English champions deservedly fell behind when 20-year old Benzema drilled the ball home past a static defence.
United came to life midway through the second half after Nani and Tevez came on for Paul Scholes and Ryan Giggs, who had a quiet 100th appearance in Europe's premier club competition.
Their pressure finally paid off after Nani's cross fell kindly for Tevez, who stretched Lyon's winless streak against English opposition to six matches.
Celtic twice led against 2006 winners Barcelona but two goals by Lionel Messi and a sublime finish from Thierry Henry handed the Catalan side the win in an absorbing contest in Glasgow.
Jan Vennegoor of Hesselink fired Celtic ahead with a diving 16th-minute header and Barry Robson made it 2-1 on his Champions League debut in the 38th minute after Messi had levelled the score following a swift one-two with Deco.
Henry curled in Barcelona's second equaliser shortly after the break and Messi had the final say with his sixth goal of the campaign when he capitalised on a defensive mix-up in the 79th minute.
Arsenal and Milan produced few fireworks in a high-tempo encounter in north London with Emmanuel Adebayor missing the best chance to steal a late winner for the Premier League leaders when he hit the crossbar in injury time.
Both sides applied a cautious approach early on and had long spells of possession before Arsenal pinned back the visitors after the hour.
Milan keeper Zeljko Kalac was rarely troubled though as Adebayor, Cesc Fabregas and Mathieu Flamini hit their shots straight at him before the Togo striker saw his effort come off the woodwork.
A goal by Semih Senturk three minutes from time gave Fenerbahce a fighting chance of advancing into the last eight at the expense of double UEFA Cup winners Sevilla.
Fener led through Serbian striker Mateja Kezman, an Edu own goal made it 1-1 before Uruguayan defender Lugano headed the hosts ahead again. Julien Escude slid in for a second equaliser on 66 minutes but Senturk grabbed the winner with a deflected effort.